Carburator issues?

[Uzi9mm]

   I have a 2002 KX500.  Gnarly pipe, Boyesen Rad valve.  Overall, bike is in good condition.  After a couple of slow priming kicks, I can usually start my 500 on the first hard kick with the choke on and a crack of throttle.  I have the idle set just a little high.  Today, I warmed it up and rode it around for about 10mins. While sitting there, after the ride, I revved it up a couple times.  The engine remained at an unusually high idle like the fuel was turned off.  I put it back in gear and rode it.  Then the idle went back to normal.  I stopped and revved it up.  And the same thing happened all over again.  I'm running some really old VP110 at 32:1 (I keep my fuel in a 5gal safety can with a spring loaded lid).  Last time I rode the bike was 2 weeks ago for an hour with no probs.  I cleaned the air cleaner ride before last.  The temp is about 20deg cooler since last time I rode.  I searched the forum for idle probs and saw that it might be a lot of things from clogged jets to air leaks and plugged fuel lines.  Just wondering if anyone else has seen anything like this before. 

[Rowdy-Yates]

I know my bike revs really high when I first start it cold. After it warms up it will come back down. Not sure why it does this but I will be rebuilding my carb soon.

[stewart]

when the moter revs or searhes for idle speed its lean pluged pilot jet ussallt ..or pull petcock out of tank and clean filter built on pet cock s top that nobody seems to look at

[hughes]

20 degrees will make a big diff. in the jetting. Might need to adjust the mixture screw (turn it in to take away some air)

[Uzi9mm]

Thanks for the info.  I'm going to start by cleaning the tank and carb.

[KXcam22]

If your pilot is jetted close you can  get to be a touch lean if the temp drops 20 deg.  Colder air is much denser hence it leans out the fuel mixture.  I get the same sometimes when I ride in snow.  1/2 turn in with the air screw usually cleans it up. Cam.

[Uzi9mm]

Thanks KXcam22, Ill try that first.

[Uzi9mm]

Found "fuzz" around the screen on the petcock and a crack in the inline fuel filter.  Besides the fuzz, the inside of the tank and carb are clean.  Looked at the jetting.  48 slow and a 168 main.  2nd position down on the needle.  I changed the slow to a 55.  1 1/2 turns on the air screw.  3rd postition down on the needle.  Runs good.  Haven't checked the plug yet.  Do any of you guys run an inline fuel filter?  Do you recommend it? 

[Johnniespeed]

 I do not run an inline filter, just the petcock, that I dont clean often enough.  Hope you get your bike sorted out soon.  I clean my air filter once a week, which is about ten to twelve gallons of fuel-riding time.    John